large, are destined sooner or later to find their way into the state institutions, whose doors are always open to let in, but never to let out.
It is to be desired, as a matter of principle, that the depositories of documents (archives, libraries, and museums) should not be too numerous; and we have pointed out that, fortunately, they are now beyond comparison less numerous than they were a hundred years ago. Could not the centralisation of documents, with its evident advantages for researchers, be carried still further? Are there not still collections of documents of which it would be hard to justify the separate existence? Perhaps; but the problem of the centralisation of documents is no longer urgent, now that the processes of reproduction have been perfected, especially as the inconveniences arising from a multitude of depositories are met by the expedient, now in general use, of allowing the documents to travel: it is now possible for the student to consult, without expense, in the public library of the city where he resides, documents belonging, say, to the libraries of St. Petersburg, Brussels, and Florence; we now rarely meet with institutions like the Archives Nationales at Paris, the British Museum at London, and the Méjanes Library at Aix-en-Provence, whose statutes absolutely prohibit all lending-out of their contents.
II. It being granted that the majority of historical documents are now preserved in public institutions (archives, libraries, and museums), Heuristic would be very easy if only good descriptive catalogues had been drawn up of all the existing collections of documents, if these catalogues were furnished with indexes, or if general repertories (alphabetical, systematic, &c.) had been made relating to them; lastly, if there were some place where it